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CHROME-VANADIUM STEELS

The product of the fusion is lixiviated with water and the solution made
up to volume in a measuring flask. In an aliquot part the chromium is
determined as indicated for the estimation of chromium in chrome steels
(the tungstic acid present does not interfere with the titration) In another
aliquot part the chromium and tungsten are precipitated with mercurous
nitrate (see Chrome Steels), the precipitate being calcined to eliminate the
mercury and the residue of tungsten trioxide and chromic oxide weighed ;
the tun^ten is thus obtained by difference. It is well to ascertain by
treatment with hydrofluoric and sulphuric acids that no silica is present
with the chromium and tungsten oxides.

2. Determination of the Carbon, Silicon, Manganese, Phosphorus
and Sulphur.—As with chrome or tungsten steels.

*

* *

The percentage compositions of some of the chrome-tungsten steels which are
most used are :

TABLE XIII
Composition of Chrome-tungsten Steels

No.
	W
	Cr
	Fe
	C
	Si
	Mn

i
	I5-5
	4'5
	79-0
	Q-43
	O-22
	0-17

O
	13-5
	8-0
	77-0
	0-60
	0-40
	0-30

3 ;
	12-0
	3-°
	83-0
	0-71
	O-2O
	0-30

4 i
	9'5
	2-05
	88-0
	o-45
	O-6O
	0-18

5
 i
	7-0
	2-1
	90-0
	O-2O
	0-25
	0-18

CHROME-VANADIUM   STEELS

These exhibit all the valuable properties of both vanadium and chrome
steels and are used for machine parts subjected to sudden stress and shock,
such as automobile parts, springs, etc.

1.  Determination of the Chromium?and Vanadium.—As in vana-

.a

dium steels containing chromium.

2.  Determination of the Carhon, Silicon, Manganese, Phosphorus
and Sulphur.—As with 'chrome or vanadium steels.

*

* *

The percentage compositions of certain types of chrome-vanadium steels are
as follows (Geiger, Eschard) :

TABLE XIV
Composition of Chrome-vanadium Steels

Used for
	C
	Si
	Mn
	P
	S
	Cr
	V

Automobile framework .
	0-263
	0-116
	0-43
	0-013
	0-009
	0-934
	0-18

Drills  .......
	0-518
	0-208
	0-86
	0-027
	0-016
	1-265
	0-16

Springs
	
	n-TVa
	0-83
	
	
	
	/-j.TQ


	
	
	
	
	
	
	

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